Porsche appears to be keen on downsizing and turbocharging several 911 models according to a document submitted by the automaker to the California Air Resources Board (CARB).

In line with the recent reveal of the 991.2 facelift, the Stuttgart-based company have already ditched the naturally-aspirated engines for the newer 3.0-liter turbocharged flat-six. These include the Carrera, Carrera S, Carrera 4S, Cabriolets, and Targa models. Based on the document, even the naturally-aspirated 911 GTS will go turbo eventually.

First revealed as a 2015 model year with a highly-tuned 3.8-liter flat-six, the 911 GTS produces 430 PS along with a torque pull of 440 Nm. With the arrival of the new 3.0-liter lump, the smaller turbocharged flat-six is able to generate 420 PS and 500 Nm of torque.

Exact output figures of the refreshed 911 GTS were not yet revealed though it is highly likely that Porsche will bump up the power substantially. Also, the GTS will supposedly be fitted with either a 7-speed manual or dual-clutch gearbox. If the GTS does go turbo, the only remaining 911 models to remain naturally-aspirated will be the R, GT3 and GT3 RS.

Beyond the powertrain update, the 991.2 update will also give the GTS a slightly altered exterior design.